Rear body structure for vehicles

ABSTRACT

A vehicle body rear part structure for a vehicle includes a rear subframe disposed below a rear side frame and extending in a vehicle body front-rear direction. The rear subframe includes a front load absorbing portion and a rear load absorbing portion which extend rearwardly of a vehicle body from an important safety related component disposed on a vehicle body rear part, are disposed on a vehicle body rear side with respect to the important safety related component, and are configured to absorb a collision load when the collision load from rearwardly of the vehicle body is applied. The rear load absorbing portion is disposed on the vehicle body rear side of the front load absorbing portion. Strength of the rear load absorbing portion against compression in an axis direction is set low, as compared with strength of the front load absorbing portion.

TECHNICAL FIELD

The present invention relates to a vehicle body rear part structure fora vehicle, and more particularly, to a vehicle body rear part structurefor a vehicle provided with a rear subframe disposed below a rear sideframe.

BACKGROUND ART

In a vehicle such as an automobile, there is known a vehicle body rearpart in which a rear subframe for supporting an engine, a transmission,and the like is disposed below a rear side frame extending in a vehiclebody front-rear direction, and the rear subframe is connected to therear side frame.

For example. Patent Literature 1 discloses a configuration in which arear subframe is disposed below a rear side frame, and the rear subframeis connected to the rear side frame. For example, Patent Literature 2discloses a configuration in which a rear subframe for mounting anengine, and a rear subframe for mounting a transmission are disposedbelow a vehicle body rear part, the rear subframe for mounting theengine is fixed to a vehicle body frame, and the rear subframe formounting the transmission is fixed to the rear subframe for mounting theengine and the vehicle body frame.

In a vehicle such as an automobile, there is a demand for improvingsafety of a passenger within a passenger compartment, when a collisionload is applied from rearwardly of a vehicle body in rear surfacecollision (rear collision). Also, in a vehicle in which a rear subframeis disposed below a rear side frame, there is a demand for improvingsafety of a passenger within a passenger compartment in rear collision.

Furthermore, in a vehicle such as an electric vehicle in which a rearsubframe is disposed below a rear side frame, when important safetyrelated components such as an engine, a power generator, and a fuel tankare disposed on a vehicle body rear part, it is desired to protect theimportant safety related components disposed on the vehicle body rearpart when a collision load is applied from rearwardly of a vehicle bodyin rear collision.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application PublicationNo. 2016-43829

Patent Literature 2: Japanese Unexamined Utility Model ApplicationPublication No. S62-8880

SUMMARY OF INVENTION

An object of the present invention is to provide, in a vehicle providedwith a rear subframe disposed below a rear side frame, a vehicle bodyrear part structure for a vehicle which enables to protect an importantsafety related component disposed on a vehicle body rear part byabsorbing a collision load in rear collision, and to improve safety of apassenger within a passenger compartment.

The present invention is directed to a vehicle body rear part structurefor a vehicle including a rear side frame extending in a vehicle bodyfront-rear direction on a vehicle body rear part, and a rear subframedisposed below the rear side frame and extending in the vehicle bodyfront-rear direction. The rear subframe includes a front load absorbingportion and a rear load absorbing portion which extend rearwardly of avehicle body from an important safety related component disposed on thevehicle body rear part, are disposed on a vehicle body rear side withrespect to the important safety related component, and are configured toabsorb a collision load when the collision load from rearwardly of thevehicle body is applied. The rear load absorbing portion is disposed onthe vehicle body rear side of the front load absorbing portion. Strengthof the rear load absorbing portion against compression in an axisdirection is set low, as compared with strength of the front loadabsorbing portion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a bottom view of a vehicle body to which a vehicle body rearpart structure for a vehicle according to a first embodiment of thepresent invention is applied.

FIG. 2 is a side view of the vehicle body to which the vehicle body rearpart structure is applied.

FIG. 3 is a bottom view of the vehicle body illustrated in FIG. 1,except for a subframe unit and a battery frame.

FIG. 4 is a bottom view of the vehicle body illustrated in FIG. 1,except for a part of the subframe unit.

FIG. 5 is a cross-sectional view of the vehicle body taken along theline Y5-Y5 in FIG. 3.

FIG. 6 is a cross-sectional view of the vehicle body taken along theline Y6-Y6 in FIG. 1.

FIG. 7 is a perspective view of the subframe unit.

FIG. 8 is a perspective view of the subframe unit except foraccessories.

FIG. 9 is a side view of the subframe unit illustrated in FIG. 8.

FIG. 10 is a bottom view of the subframe unit illustrated in FIG. 8.

FIG. 11 is a perspective view illustrating a frame connecting portionfor connecting a rear subframe and a rear side frame.

FIG. 12 is a perspective view illustrating a branch frame member of thesubframe unit.

FIG. 13 is a perspective view illustrating a frame connecting portionfor connecting the rear subframe and the battery frame.

FIG. 14 is another perspective view illustrating a frame connectingportion for connecting the rear subframe and the battery frame.

FIG. 15 is a perspective view illustrating a lower frame member of thesubframe unit.

FIG. 16 is a cross-sectional view of a rear subframe unit taken alongthe line Y16-Y16 in FIG. 10.

FIG. 17 is an explanatory diagram illustrating how an accessory ismounted on the rear subframe.

FIG. 18 is an explanatory diagram illustrating a rear support hanger forsupporting a silencer.

FIG. 19, of sections (a) to (c), are explanatory diagrams illustratinghow the silencer moves in rear collision.

FIG. 20 is a bottom view of a vehicle body to which a vehicle body rearpart structure for a vehicle according to a second embodiment of thepresent invention is applied.

FIG. 21 is a side view of the vehicle body to which the vehicle bodyrear part structure is applied.

FIG. 22 is a perspective view illustrating essential parts of thevehicle body rear part structure.

FIG. 23 is a cross-sectional view of a connecting portion between alower frame member and an upper cross portion.

FIG. 24 is a cross-sectional view of a connecting portion between thelower frame member and a battery frame.

DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present invention are describedwith reference to the accompanying drawings.

FIG. 1 is a bottom view of a vehicle body to which a vehicle body rearpart structure for a vehicle according to a first embodiment of thepresent invention is applied. FIG. 2 is a side view of the vehicle bodyto which the vehicle body rear part structure for a vehicle is applied.FIG. 3 is a bottom view of the vehicle body illustrated in FIG. 1,except for a subframe unit and a battery frame. FIG. 4 is a bottom viewof the vehicle body illustrated in FIG. 1, except for a part of thesubframe unit. FIG. 5 is a cross-sectional view of the vehicle bodytaken along the line Y5-Y5 in FIG. 3. FIG. 6 is a cross-sectional viewof the vehicle body taken along the line Y6-Y6 in FIG. 1.

A vehicle body 1 to which a vehicle body rear part structure for avehicle according to an embodiment of the present invention is appliedis a vehicle body of an electric vehicle or the like provided with adrive motor as a drive source for driving the vehicle, and a battery forstoring electric power to be supplied to the drive motor. A rangeextender device for extending a cruising distance is provided in thevehicle body 1. The range extender device includes a power generator forgenerating driving electric power to be supplied to the battery, and anengine as a drive source for driving the power generator. In the vehiclebody 1, the drive motor is disposed on a vehicle body front part, thebattery is disposed below a passenger compartment floor portion, and therange extender device is disposed on a vehicle body rear part.

As illustrated in FIGS. 1 to 6, on the vehicle body rear part in thevehicle body 1, a pair of left and right rear side frames 2 extending ina vehicle body front-rear direction, and a rear subframe 50 extending inthe vehicle body front-rear direction along the left and right rear sideframes 2 at a position below the left and right rear side frames 2, aredisposed. The rear side frames 2 and the rear subframe 50 are formed ofa plate-shaped member using a metal material.

Also on the vehicle body rear part, a rear floor portion 3 constitutedof a rear floor panel spanning between the left and right rear sideframes 2 and extending in the vehicle body front-rear direction, and afirst cross member 4 spanning between the left and right rear sideframes 2 on a lower surface side of the rear floor portion 3 aredisposed.

An opening portion 3 a is formed in the rear floor portion 3 fordisposing a range extender device 40, in which a power generator 41 forgenerating driving electric power to be supplied to a battery 20, and anengine 42 for driving the power generator 41 are integrally mounted. Thefirst cross member 4 is disposed on a vehicle body front side of theopening portion 3 a.

The rear side frame 2 is formed into a substantially U-shape in crosssection and is mounted on a lower surface of the rear floor portion 3,and, in cooperation with the rear floor portion 3, is formed into aclosed cross section of a substantially rectangular shape in crosssection extending in the vehicle body front-rear direction. The firstcross member 4 is formed into a substantially hat shape in cross sectionand is mounted on a lower surface of the rear floor portion 3, and, incooperation with the rear floor portion 3, is formed into a closed crosssection of a substantially rectangular shape in cross section extendingin the vehicle width direction.

A crash can 6, as a load absorbing portion extending in the vehicle bodyfront-rear direction, is formed on a vehicle body rear end of each ofthe left and right rear side frames 2. The crash cans 6 are respectivelyattached to both ends of a side frame bumper reinforcement 5, which isdisposed within a rear bumper (not illustrated) extending in the vehiclewidth direction.

As illustrated in FIG. 5, the crash can 6 is formed into a closed crosssection of a substantially polygonal shape in cross section in which anorthogonal cross section substantially orthogonal to an axis directionbeing the vehicle body front-rear direction has sides of a number largerthan the number of sides of a rectangle. Specifically, the crash can 6includes a closed cross-sectional portion 6 a of a substantially crossshape in cross section, and a plurality of recess portions 6 b, each ofwhich extends in a direction substantially orthogonal to the axisdirection. With this structure, when a collision load is applied fromrearwardly of the vehicle body, the crash can 6 is folded back to becollapsed and deformed, and absorbs the collision load.

The crash can 6 is integrally formed into a closed cross section bysubjecting a pipe member to hydro-forming process or the like.Alternatively, it is possible to form the crash can 6 into asubstantially cross shape in cross section by joining a firstplate-shaped member formed into a projection shape in cross section andprojecting outwardly in the vehicle width direction, and a secondplate-shaped member formed into a projection shape in cross section andprojecting inwardly in the vehicle width direction.

As illustrated in FIG. 2, the crash can 6 is connected to the rear sideframe 2 by engaging a first plate member 7 and a second plate member 8using a bolt and a nut, the first plate member 7 being fixedly mountedto the crash can 6 by welding or the like and extending in a directionsubstantially orthogonal to the vehicle body front-rear direction, thesecond plate member 8 being fixedly mounted to the rear side frame 2 bywelding or the like and extending in a direction substantiallyorthogonal to the vehicle body front-rear direction.

In the vehicle body 1, the rear side frame 2 is formed into a closedcross section in cooperation with the rear floor portion 3.Alternatively, the rear side frame 2 itself may be formed into a closedcross section shape of a substantially rectangular shape in crosssection. Furthermore, the crash can 6 is provided on a vehicle body rearpart of the rear side frame 2 via the first plate member 7 and thesecond plate member 8. Alternatively, the crash can 6 may be integrallyformed with the rear side frame 2.

Furthermore, in the vehicle body 1, by providing the crash can 6 on therear side frame 2, a portion of the rear side frame 2 where the crashcan 6 is formed becomes a load absorbing portion, that is, a portionwhere the strength against compression in the axis direction is small,as compared with the other portion of the rear side frame 2.Alternatively, a load absorbing portion may be provided on the rear sideframe 2 by reducing a thickness of a part of steel plate forming therear side frame 2 to decrease the strength against compression in theaxis direction, for instance.

A front end of the rear side frame 2 is overlapped and joined to a rearend of a kick-up frame 9. A front end of the kick-up frame 9 is joinedto a second cross member 12 spanning between left and right side sills11 and extending in the vehicle width direction. The kick-up frame 9 isinclined outwardly in the vehicle width direction and downwardly of thevehicle body, as extending forwardly of the vehicle body. The left andright side sills 11 are disposed on both sides in the vehicle widthdirection of a passenger compartment floor portion 10 extending in thevehicle body front-rear direction, the passenger compartment floorportion 10 being constituted of a front floor panel forming a floorsurface of a passenger compartment.

A kick-up portion 13 constituted of a kick-up panel spans between theleft and right kick-up frames 9, the kick-up panel extending while beinginclined upwardly of the vehicle body from a rear end of the passengercompartment floor portion 10, as extending rearwardly of the vehiclebody. The rear floor portion 3 is provided in such a way as to extendfrom the kick-up portion 13 rearwardly of the vehicle body.

The kick-up frame 9 is mounted on a lower surface of the kick-up portion13 while being formed into a substantially hat shape in cross section,and is formed, in cooperation with the kick-up portion 13, into a closedcross section of a substantially rectangular shape in cross sectionextending in the vehicle body front-rear direction. The second crossmember 12 is mounted on a lower surface of the passenger compartmentfloor portion 10 while being formed into a substantially hat shape incross section, and is formed, in cooperation with the passengercompartment floor portion 10, into a closed cross section of asubstantially rectangular shape in cross section extending in thevehicle width direction.

As illustrated in FIG. 3, in the passenger compartment floor portion 10,a floor tunnel portion 14 is formed on a middle portion in the vehiclewidth direction, the floor tunnel portion 14 extending in the vehiclebody front-rear direction and bulging upwardly of the vehicle body. Afloor frame 15 extending in the vehicle body front-rear direction ismounted substantially on a middle between the floor tunnel portion 14,and the left and right side sills 11. A tunnel reinforcement 16 ismounted on both sides of the floor tunnel portion 14 in the vehiclewidth direction. The floor frame 15 and the tunnel reinforcement 16 areformed into a substantially hat shape in cross section, and joined tothe passenger compartment floor portion 10.

In the vehicle body 1, the battery 20 is disposed below the passengercompartment floor portion 10. As illustrated in FIG. 6, the battery 20is supported by the vehicle body 1, by being mounted on a battery frame30 which supports the battery 20 in a state that the battery 20 ismounted on a battery tray 21, and by the battery frame 30 beingconnected to the passenger compartment floor portion 10.

The battery frame 30 includes: a front frame (not illustrated) disposedon the vehicle body front side and extending in the vehicle widthdirection; a rear frame 31 disposed on the vehicle body rear side andextending in the vehicle width direction; and both side lateral frames32 extending in the vehicle body front-rear direction while respectivelyconnecting both sides of the front frame in the vehicle width direction,and both sides of the rear frame 31 in the vehicle width direction. Theboth side lateral frames 32 are disposed on a vehicle body lower side ofthe left and right floor frames 15, and are mounted on the floor frames15.

As illustrated in FIG. 6, each of the front frame, the rear frame 31,and the both side lateral frames 32 is constituted by an upper frame 33of a substantially L-shape in cross section and constituting a vehiclebody upper part of the battery frame 30, and a lower frame 34 of asubstantially L-shape in cross section and constituting a vehicle bodylower part of the battery frame 30. The upper frame 33 and the lowerframe 34 are joined to each other to be formed into a closed crosssection of a substantially rectangular shape in cross section. A flangeportion 30 a extending substantially horizontally and inwardly in thevehicle width direction is formed on the battery frame 30. The batterytray 21 is mounted on the flange portion 30 a. The battery 20 issupported on the battery frame 30.

The battery frame 30, specifically, the lateral frame 32 is disposedsubstantially along the floor frame 15, and is connected to the floorframe 15. As illustrated in FIG. 6, regarding a frame connecting portion35 connecting the battery frame 30 and the floor frame 15, connection isperformed by placing an upper surface portion 30 b of the battery frame30 on a bottom surface portion 15 a of the floor flame 15 and using abolt B1 and a nut N1. A plurality of the frame connecting portions 35are provided on the lateral frame 32 in the vehicle body front-reardirection.

In the vehicle body 1, the range extender device 40 including the powergenerator 41 and the engine 42 is disposed on the vehicle body rearpart. The range extender device 40 is an accessary being an importantsafety related component in view of that the power generator 41 uses ahigh voltage. The range extender device 40 is disposed within theopening portion 3 a of the rear floor portion 3, and is provided in sucha way as to project upwardly of the vehicle body and downwardly of thevehicle body with respect to the rear floor portion 3.

On the vehicle body rear part also, a silencer 44 and a catalytic device45 as exhaust system parts are disposed on an exhaust pipe 43 extendingfrom the engine 42. The silencer 44 reduces noise generated when exhaustgas from the engine 42 is released into the air. The catalytic device 45purifies exhaust gas from the engine 42. The silencer 44 and thecatalytic device 45 are accessories which are not important safetyrelated components, and are disposed in such a way as to extend in thevehicle width direction on the vehicle body lower side of the rear floorportion 3. Specifically, the catalytic device 45 is disposed on thevehicle body rear side of the range extender device 40, and the silencer44 is disposed on the vehicle body rear side of the catalytic device 45.The silencer 44 and the catalytic device 45 are integrally connected bya connecting member 46.

Accessories to be disposed on the vehicle body rear part, specifically,the range extender device 40, the silencer 44, and the catalytic device45 constitute a subframe unit 60 as a one-piece unit by being integrallymounted on the rear subframe 50. The entirety of the subframe unit 60 ismounted in the vehicle body 1. In this way, integrally forming theaccessories 40, 44, and 45 to be disposed on the vehicle body rear part,and the rear subframe 50 as the one-piece unit 60 makes it easy to mountthe one-piece unit 60 in the vehicle body 1, and enables to improveproductivity in manufacturing the vehicle body, and safety.

On the vehicle body rear part also, a torsion beam suspension deviceincluding a pair of left and right trailing arms (not illustrated)extending in the vehicle body front-rear direction, and a torsion beam17 (see the broken line in FIG. 2) connecting the pair of left and righttrailing arms and extending in the vehicle width direction is provided.In the vehicle body 1, the torsion beam 17 is disposed on the vehiclebody front side of the range extender device 40, on the vehicle bodyrear side with respect to the battery frame 30, and on a vehicle bodyupper side of a later-described lower frame member 71 of the rearsubframe 50.

FIG. 7 is a perspective view of the subframe unit. FIG. 8 is aperspective view of the subframe unit except for accessories. FIG. 9 isa side view of the subframe unit illustrated in FIG. 8. FIG. 10 is abottom view of the subframe unit illustrated in FIG. 8. As illustratedin FIGS. 7 to 10, the subframe unit 60 is constituted by integrallymounting the range extender device 40, the silencer 44, and thecatalytic device 45 on the rear subframe 50.

The rear subframe 50 includes: an upper frame member 51 extending in thevehicle body front-rear direction along the rear side frame 2; a branchframe member 61 joined to the upper frame member 51 and branched in sucha way as to extend from a middle of the upper frame member 51 in thevehicle body front-rear direction, forwardly of the vehicle body anddownwardly of the vehicle body; and the lower frame member 71 disposedon the vehicle body lower side with respect to the upper frame member51, and extending substantially horizontally and forwardly of thevehicle body from the branch frame member 61.

A subframe bumper reinforcement 18, which is disposed within a rearbumper (not illustrated) extending in the vehicle width direction, isconnected also to the rear subframe 50. Vehicle body rear ends of theleft and right upper frame members 51 are respectively connected to bothends of the subframe bumper reinforcement 18. The rear subframe 50 isformed laterally symmetrical in the vehicle width direction.

The upper frame member 51 includes left and right upper frame portions52 respectively extending in the vehicle body front-rear direction alongthe left and right rear side frames 2, and an upper cross portion 53extending in the vehicle width direction and connecting the left andright upper frame portions 52 at middle portions thereof in the vehiclewidth direction.

The upper frame portion 52 includes a load absorbing portion 54, whichis formed into a closed cross section, extends rearwardly of the vehiclebody with respect to the range extender device 40, and absorbs acollision load, when the collision load is applied from rearwardly ofthe vehicle body to a position on the vehicle body rear side withrespect to the range extender device 40.

As illustrated in FIG. 8, the load absorbing portion 54 includes a frontload absorbing portion 54 a disposed on the vehicle body front side, anda rear load absorbing portion 54 b disposed on the vehicle body rearside with respect to the front load absorbing portion 54 a. The frontload absorbing portion 54 a and the rear load absorbing portion 54 b areformed into a same closed cross section on an orthogonal cross sectionsubstantially orthogonal to the vehicle body front-rear direction, andhave a closed cross section portion of a substantially cross shape incross section similarly to the crash can 6. The rear load absorbingportion 54 b is formed to have a small thickness of steel plate and asmall strength against compression in the axis direction, as comparedwith the front load absorbing portion 54 a.

Each of the front load absorbing portion 54 a and the rear loadabsorbing portion 54 b is formed into a substantially cross shape incross section by joining a first plate-shaped member and a secondplate-shaped member, the first plate-shaped member being formed into aprojection shape in cross section and projecting outwardly in thevehicle width direction, the second plate-shaped member being formedinto a projection shape in cross section and projecting inwardly in thevehicle width direction. However, structures of the load absorbingportions 54 a and 54 b are not limited to the above.

In the vehicle body 1, the silencer 44 and the catalytic device 45 areprovided on the vehicle body front side of the load absorbing portion 54of the rear subframe 50, at a position where the silencer 44 and thecatalytic device 45 overlap the load absorbing portion 54, specificallythe front load absorbing portion 54 a, in the vehicle body front-reardirection (see FIG. 2).

The upper frame portion 52 further includes a front frame portion 55 onthe vehicle body front side with respect to the load absorbing portion54. A vehicle body rear part of the front frame portion 55 is formedinto a closed cross section of a substantially hexagonal shape in crosssection, and a vehicle body front part thereof is formed into a closedcross section of a substantially rectangular shape in cross section.

As illustrated in FIG. 4, the front frame portion 55 extends outwardlyin the vehicle width direction, as extending forwardly of the vehiclebody, and is connected to a vehicle body front part of the rear sideframe 2 using a bolt and a nut. The front frame portion 55 is formed tohave a large thickness of steel plate and a large strength againstcompression in the axis direction, as compared with the front loadabsorbing portion 54 a and the rear load absorbing portion 54 b.

As illustrated in FIG. 2, a load absorbing portion of the side of theside frame provided on the rear side frame 2, that is, the crash can 6(hereinafter, also referred to as a load absorbing portion 6), and theload absorbing portion 54 of the side of the subframe provided on therear subframe 50, are provided in such a way that a rear end of the loadabsorbing portion 54 of the side of the subframe is disposed on thevehicle body front side with respect to a rear end of the load absorbingportion 6 of the side of the side frame, and a front end of the loadabsorbing portion 54 of the side of the subframe is disposed on thevehicle body front side with respect to a front end of the loadabsorbing portion 6 of the side of the side frame.

On the upper frame portion 52, a plurality of frame connecting portions56 connecting the rear subframe 50 and the rear side frame 2 are alsoprovided. The plurality of the frame connecting portions 56 are providedto be separated away from one another in the vehicle body front-reardirection. A front frame connecting portion 56 a and a rear frameconnecting portion 56 b connecting the load absorbing portion 54 of therear subframe 50 and the rear side frame 2 are provided in the vehiclebody 1.

FIG. 11 is a perspective view illustrating a frame connection memberconnecting the rear subframe and the rear side frame, and illustrates aframe connecting member 80 constituting the rear frame connectingportion 56 b. Regarding the rear frame connecting portion 56 b, the rearsubframe 50, and the rear side frame 2 disposed in proximity to the rearsubframe 50 are connected by the frame connecting member 80.

As illustrated in FIG. 11, the frame connecting member 80 includes aperipheral wall portion 83 and a load transmitting portion 84, theperipheral wall portion 83 extending in the vehicle width direction, andbeing formed into a closed cross section of a substantially rectangularshape in cross section on an orthogonal cross section orthogonal to thevehicle width direction, the load transmitting portion 84 being disposedwithin the peripheral wall portion 83 and extending in the vehicle bodyfront-rear direction. The peripheral wall portion 83 is constituted byjoining an upper frame 81 and a lower frame 82, the upper frame 81 beingformed into a substantially U-shape in cross section and constituting avehicle body upper part of the frame connecting member 80, the lowerframe 82 being formed into a substantially U-shape in cross section andconstituting a vehicle body lower part of the frame connecting member80.

The peripheral wall portion 83 includes an upper surface portion 83 a, alower surface portion 83 b, and lateral surface portions 83 c on bothsides in the vehicle body front-rear direction. The peripheral wallportion 83 is formed into a closed cross section. The load transmittingportion 84 has a closed cross-sectional portion 84 a which is formedinto a substantially cross shape in cross section by joining a firstplate-shaped member 85 formed into a projection shape in cross section,and a second plate-shaped member 86 formed into a projection shape incross section.

The closed cross-sectional portion 84 a of the load transmitting portion84 is formed to have a same shape as a closed cross-sectional portion ofthe front load absorbing portion 54 a and a closed cross-sectionalportion of the rear load absorbing portion 54 b of the rear subframe 50.The load transmitting portion 84 is formed in such a way that a vehiclebody front part of the load transmitting portion 84 is abutted on andjointed to a vehicle body front part of the peripheral wall portion 83,and a vehicle body rear part of the load transmitting portion 84 isabutted on and jointed to a vehicle body rear part of the peripheralwall portion 83, in a state that both lateral surface portions 85 a ofthe first plate-shaped member 85 and both lateral surface portions 86 aof the second plate-shaped member 86 are joined to one another.

On the outer side of the frame connecting member 80 in the vehicle widthdirection, a bolt insertion hole 83 d is formed in the upper surfaceportion 83 a and the lower surface portion 83 b, and a tubular member 87of a substantially tubular shape in association with the bolt insertionhole 83 d for receiving a bolt B2 is fixedly mounted on the uppersurface portion 83 a.

The frame connecting member 80 is disposed between the front loadabsorbing portion 54 a and the rear load absorbing portion 54 b in sucha way that the closed cross-sectional portion 84 a of the loadtransmitting portion 84 is aligned, in the vehicle body front-reardirection, with a closed cross-sectional portion of the front loadabsorbing portion 54 a and a closed cross-sectional portion of the rearload absorbing portion 54 b, and is joined and connected to the frontload absorbing portion 54 a and the rear load absorbing portion 54 b.

Further, as illustrated in FIG. 3, the frame connecting member 80 isconnected to the rear side frame 2 by screwing the bolt B2 in a nut (notillustrated) welded to a vehicle body upper part of a lower surfaceportion 2 a of the rear side frame 2 in a state that the bolt insertionhole 83 d provided in the upper surface portion 83 a of the frameconnecting member 80 corresponds to a bolt insertion hole 2 b providedin the lower surface portion 2 a of the rear side frame 2, and that theframe connecting member 80 is disposed on the vehicle body lower side ofthe rear side frame 2.

Also regarding the front frame connecting portion 56 a, the rearsubframe 50 and the rear side frame 2 are connected by a frameconnecting member 80. The frame connecting member 80 includes aperipheral wall portion 83 and a load transmitting portion 84 similarlyformed on the rear frame connecting portion 56 b. A bolt insertion hole83 d is formed on the outer side of the frame connecting member 80 inthe vehicle width direction, and a tubular member 87 is fixedly mountedon an upper surface portion 83 a.

In the front frame connecting portion 56 a, the frame connecting member80 is disposed between the front load absorbing portion 54 a and thefront frame portion 55 in such a way that a closed cross-sectionalportion 84 a of the load transmitting portion 84 is aligned with aclosed cross-sectional portion of the front load absorbing portion 54 ain the vehicle body front-rear direction. The frame connecting member 80is joined and connected to the front load absorbing portion 54 a and thefront frame portion 55.

The frame connecting member 80 of the front frame connecting portion 56a is also connected to the rear side frame 2 by screwing a bolt B2 intoa nut welded on a vehicle body upper part of the lower surface portion 2a of the rear side frame 2 in a state that the bolt insertion hole 83 dprovided in the upper surface portion 83 a of the frame connectingmember 80 corresponds to the bolt insertion hole 2 b provided in thelower surface portion 2 a of the rear side frame 2, and that the frameconnecting member 80 is disposed on the vehicle body lower side of therear side frame 2.

The left and right frame connecting members 80 constituting the frontframe connecting portion 56 a are connected by a sub cross member 90formed into a closed cross section and extending in the vehicle widthdirection. The upper cross portion 53 is formed by joining both ends ofthe sub cross member 90 in the vehicle width direction to the peripheralwall portions 83 of the left and right frame connecting members 80. Inthe sub cross member 90, an inclined surface 90 a (see FIGS. 10 and 16),which is inclined downwardly of the vehicle body as extending forwardlyof the vehicle body, is further provided on a middle portion in thevehicle width direction. A later-described guide panel (guide portion91) is mounted on the inclined surface 90 a.

FIG. 12 is a perspective view illustrating the branch frame member ofthe subframe unit. As illustrated in FIG. 12, the branch frame member 61includes: a rear surface portion 62 disposed on the vehicle body rearside and extending while being inclined downwardly of the vehicle body,as extending forwardly of the vehicle body; a front surface portion 63disposed on the vehicle body front side and extending downwardly of thevehicle body in a substantially vertical direction; a bottom surfaceportion 64 disposed on the vehicle body lower side and extending in thevehicle body front-rear direction and in a substantially horizontaldirection; and both side lateral surface portions 65 connecting innerends and outer ends in the vehicle width direction of each of the rearsurface portion 62, the front surface portion 63, and the bottom surfaceportion 64, and disposed, in a direction substantially orthogonal to thevehicle width direction, to be separated away from each other in thevehicle width direction.

The lateral surface portion 65 of the branch frame member 61 is formedinto a substantially right angled trapezoidal shape in which a vehiclebody upper part has a long length in the vehicle body front-reardirection, as compared with a vehicle body lower part. An opening 65 aof a substantially inverted triangular shape is formed in the lateralsurface portion 65. The branch frame member 61 is connected to the upperframe member 51 by joining, to the upper frame member 51, a flangeportion 66 provided on both side lateral surface portions 65 andextending upwardly of the vehicle body.

FIG. 13 is a perspective view illustrating the frame connecting portionconnecting the rear subframe and the battery frame. FIG. 14 is anotherperspective view illustrating the frame connecting portion connectingthe rear subframe and the battery frame. FIG. 15 is a perspective viewillustrating the lower frame member of the subframe unit.

As illustrated in FIGS. 13 to 15, in a frame connecting portion 70connecting the rear subframe 50 and the battery frame 30, the lowerframe member 71 of the rear subframe 50 and the battery frame 30 areconnected. The lower frame member 71 includes a closed cross-sectionalportion 74, which is formed into a closed cross section on an orthogonalcross section orthogonal to the vehicle body front-rear direction, byjoining an upper frame 72 of a substantially U-shape in cross section,constituting a vehicle body upper part of the lower frame member 71, anda lower frame 73 of a substantially U-shape in cross section,constituting a vehicle body lower part of the lower frame member 71.

An inner portion in the vehicle width direction of the lower framemember 71 is linearly formed in the vehicle body front-rear direction,and an outer portion in the vehicle width direction of the lower framemember 71 extends inclined outwardly in the vehicle width direction, asextending forwardly of the vehicle body. In other words, the lower framemember 71 has a substantially right angled triangular shape in which awidth of a vehicle body front part in the vehicle width direction islarge, as compared with that of a vehicle body rear part in a plan view.

As illustrated in FIG. 15, a first recess portion 75 is formed in amiddle portion in the vehicle width direction in a vehicle body frontend of an upper surface portion 71 a of the lower frame member 71, thefirst recess portion 75 being recessed in a shape of a substantiallyfrustum of a quadrilateral pyramid, in such a way that a ridge lineextending in the vehicle body front-rear direction is formed on an innerportion of the closed cross-sectional portion 74. A second recessportion 76 is formed in a middle portion in the vehicle width directionin a vehicle body front end of a lower surface portion 71 b, the secondrecess portion 76 being recessed in a shape of a substantially quadraticprism, in such a way that a ridge line extending in the vehicle bodyfront-rear direction is formed on an inner portion of the closedcross-sectional portion 74.

A front extension portion 73 a and a rear extension portion 73 brespectively extending forwardly of the vehicle body and rearwardly ofthe vehicle body with respect to the upper frame 72 are provided on thelower frame 73 of the lower frame member 71.

The lower frame member 71 is connected to the battery frame 30 by a nut(not illustrated) fixedly attached to an upper surface of a bottomsurface portion 30 c of the battery frame 30 and a bolt B3 to be screwedin the nut, in a state that a vehicle body front part of the closedcross-sectional portion 74 is disposed to face the battery frame 30, andthat the front extension portion 73 a is overlapped on the bottomsurface portion 30 c of the battery frame 30. A lower frame of the rearframe 31 extends in such a way as to cover the lateral frame 32, on thevehicle body rear side of the lateral frame 32 of the battery frame 30.

As illustrated in FIGS. 1 and 13, the lateral frame 32 of the batteryframe 30 extends in the vehicle body front-rear direction, while beingoffset to a middle side in the vehicle body front-rear direction withrespect to the rear subframe 50, and being offset outwardly in thevehicle width direction with respect to the rear subframe 50.

Specifically, the lateral frame 32 extends in the vehicle bodyfront-rear direction in such a way that a centerline C2 of the lateralframe 32 is offset outwardly in the vehicle width direction with respectto a centerline C1 of the rear subframe 50 in the vehicle widthdirection (in other words, a line passing through a center of the loadabsorbing portion 54 in the vehicle width direction, and extending inthe vehicle body front-rear direction).

The lower frame member 71 includes: an inclined portion 77 extendingwhile being inclined outwardly in the vehicle width direction, asextending forwardly of the vehicle body, to face the lateral frame 32;and a widening portion 78 widening inwardly in the vehicle widthdirection from the inclined portion 77 up to a position where the lowerframe member 71 linearly extends in the vehicle body front-reardirection, and facing the rear frame 31.

The inclined portion 77 is formed by an outer portion of the lower framemember 71 in the vehicle width direction. The widening portion 78 isformed by an inner portion of the lower frame member 71 in the vehiclewidth direction on the vehicle body front side. A vehicle body rear partof the lower frame member 71 has a width substantially equal to a widthof the upper frame member 51 and the branch frame member 61 in thevehicle width direction.

The lower frame member 71 is further connected to the branch framemember 61 by a nut (not illustrated) fixedly attached to an uppersurface of the bottom surface portion 64 of the branch frame member 61and a bolt B4 to be screwed in the nut, in a state that a vehicle bodyrear part of the closed cross-sectional portion 74 is disposed facingthe front surface portion 63 of the branch frame member 61, and that therear extension portion 73 b is overlapped with the bottom surfaceportion 64 of the branch frame member 61.

FIG. 16 is a cross-sectional view of the subframe unit taken along theline Y16-Y16 in FIG. 10. As illustrated in FIG. 16, the rear subframe 50includes a guide portion 91, which is disposed on the vehicle body rearside with respect to the range extender device 40, and on the vehiclebody front side with respect to the silencer 44 and the catalytic device45. The guide portion 91 is constituted of a guide panel which extendswhile being inclined downwardly of the vehicle body, as extendingforwardly of the vehicle body, and is configured to guide the silencer44 when a collision load is applied from rearwardly of the vehicle body.

The guide portion 91 includes a vertical wall portion 92 extending whilebeing inclined downwardly of the vehicle body, as extending forwardly ofthe vehicle body. The guide portion 91 extends downwardly of the vehiclebody with respect to the range extender device 40 in such a way as tocover the range extender device 40 from the vehicle body rear side. Aplurality of recess portions 92 a, specifically, three recess portions92 a are provided in the vertical wall portion 92 to be separated awayfrom one another in the vehicle width direction. Each of the recessportions 92 a extends vertically of the vehicle body, and is recessedforwardly of the vehicle body. Thus, a plurality of ridge linesextending vertically of the vehicle body are formed on the guide portion91 by the recess portions 92 a.

As illustrated in FIG. 8, a mounting bracket 93 of a substantially hatshape in cross section is mounted on both sides, in the vehicle widthdirection, of a vehicle body front part of the guide portion 91, in sucha way as to cover a vehicle body front part of the recess portion 92 a.As illustrated in FIG. 16, the mounting bracket 93 is mounted on theinclined surface 90 a of the sub cross member 90 using a bolt and a nut.Thus, the guide portion 91 is connected to the upper cross portion 53.The guide portion 91 extends rearwardly of the vehicle body with respectto the upper cross portion 53. A portion 91 a extending rearwardly ofthe vehicle body with respect to the upper cross portion 53 is supportedon the upper cross portion 53 in a cantilever state.

The guide portion 91 further includes a bottom surface portion 94extending forwardly of the vehicle body from a vehicle body lower partof the vertical wall portion 92. Flange portions 94 a provided on bothsides, in the vehicle width direction, of the bottom surface portion 94are connected to the bottom surface portion 64 of the branch framemember 61 together with the rear extension portion 73 b of the lowerframe member 71 using a bolt B4 and a nut. Flange portions 92 b providedon both sides, in the vehicle width direction, of a vehicle body lowerpart of the vertical wall portion 92 are connected to the rear surfaceportion 62 of the branch frame member 61 using a bolt B5 and a nut (seeFIGS. 10 and 13).

The guide portion 91 is connected to a front end of the load absorbingportion 54 provided on the upper frame member 51 via the upper crossportion 53, and is connected to the bottom surface portion 64 of thebranch frame member 61 and the rear extension portion 73 b of the lowerframe member 71. It is also possible to use the bottom surface portion94 of the guide portion 91 as a jack contact portion where a garage jackcomes into contact at maintenance work or the like, for example.

FIG. 17 is an explanatory diagram illustrating how an accessory ismounted on the rear subframe, and illustrates a portion associated withmounting an accessory. In the drawings except for FIGS. 17 to 19,illustration of a mounting structure of an accessory on the rearsubframe 50 is omitted. As illustrated in FIG. 17, the range extenderdevice 40 is mounted on the upper frame member 51 of the rear subframe50 via an elastic member by left and right lateral support portions 40 aprovided on both sides in the vehicle width direction, and is mounted onthe sub cross member 90 via an elastic member by a rear support portion40 b provided on the vehicle body rear side.

The silencer 44 and the catalytic device 45 are mounted on the rearsubframe 50 by a front support hanger 100, and a rear support hanger 110disposed on the vehicle body rear side with respect to the front supporthanger 100.

The front support hanger 100 includes: a silencer rod 101, which isfixed to both sides, in the vehicle width direction, of the exhaust pipe43 on the upstream side with respect to the silencer 44, and a distalend of which extends in the vehicle width direction; a subframe rod 102,which is fixed to the frame connecting member 80 of the rear frameconnecting portion 56 b of the rear subframe 50, and a distal end ofwhich extends in the vehicle width direction; and a rubber member 103 asan elastic body into which the silencer rod 101 and the subframe rod 102are inserted.

The rubber member 103 has a substantially elliptical plate shape and ismade of an elastic material such as rubber. Insertion holes 103 a and103 b, which extend in the axis direction of the rubber member 103, andinto which the silencer rod 101 and the subframe rod 102 arerespectively inserted, are provided in the rubber member 103. The twoinsertion holes 103 a and 103 b are provided in the rubber member 103 ofthe front support hanger 100 in such a way as to extend in the vehiclewidth direction while being separated away from each other in thevehicle body front-rear direction.

The silencer rod 101 includes, at a distal end thereof, a silencerinsertion portion 101 a extending in the vehicle width direction, andconfigured to be inserted into the insertion hole 103 a of the rubbermember 103. The subframe rod 102 includes, at a distal end thereof, asubframe insertion portion 102 a extending in the vehicle widthdirection, and configured to be inserted into the insertion hole 103 bof the rubber member 103.

The front support hanger 100 is configured in such a way that thesilencer insertion portion 101 a of the silencer rod 101 and thesubframe insertion portion 102 a of the subframe rod 102 arerespectively inserted into the insertion holes 103 a and 103 b of therubber member 103, and that the silencer 44 and the catalytic device 45are supported on the rear subframe 50 via the rubber member 103.

FIG. 18 is an explanatory diagram illustrating the rear support hangersupporting the silencer, and schematically illustrates a portionassociated with the rear support hanger. As illustrated in FIGS. 17 and18, the rear support hanger 110 is provided on each side, in the vehiclewidth direction, of a vehicle body rear part of the silencer 44. Therear support hanger 110 includes: a silencer rod 111, which is fixed tothe silencer 44 and a distal end of which extends in the vehicle bodyfront-rear direction; a subframe rod 112, which is fixed to the subframebumper reinforcement 18 of the rear subframe 50, and a distal end ofwhich extends in the vehicle body front-rear direction; and a rubbermember 113 as an elastic body into which the silencer rod 111 and thesubframe rod 112 are inserted.

The rubber member 113 has a substantially elliptical plate shape and ismade of an elastic material such as rubber. Insertion holes 113 a and113 b, which extend in the axis direction of the rubber member 113, andinto which the silencer rod 111 and the subframe rod 112 arerespectively inserted, are provided in the rubber member 113. The twoinsertion holes 113 a and 113 b are provided in the rubber member 113 ofthe rear support hanger 110 in such a way as to extend in the vehiclebody front-rear direction, while being separated away from each othervertically of the vehicle body and in the vehicle width direction.

The silencer rod 111 includes, at a distal end thereof, a silencerinsertion portion 111 a extending in the vehicle body front-reardirection, and configured to be inserted into the insertion hole 113 aof the rubber member 113. The silencer rod 111 further includes anelastic body movement restraining portion 111 b, which is disposed onforwardly of the vehicle body with respect to the silencer insertionportion 111 a, is bent, and is configured to restrain the rubber member113 from moving forwardly of the vehicle body with respect to thesilencer insertion portion 111 a.

The subframe rod 112 includes, at a distal end thereof, a subframeinsertion portion 112 a extending in the vehicle body front-reardirection, and configured to be inserted into the insertion hole 113 bof the rubber member 113. The subframe rod 112 further includes asubframe insertion allowing portion 112 b, which extendsstraightforwardly by a predetermined distance in the vehicle bodyfront-rear direction continued from the subframe insertion portion 112 atoward a vehicle body rear part, to allow the subframe insertion portion112 a to insert into the insertion hole 113 b.

The subframe rod 112 further includes an elastic body insertionrestraining portion 112 c, which is bent on the vehicle body rear partof the subframe insertion allowing portion 112 b, to restrain a portionof a vehicle body rear side with respect to the subframe insertionallowing portion 112 b from being inserted into the rubber member 113.

The rear support hanger 110 is configured in such a way that thesilencer insertion portion 111 a of the silencer rod 111 and thesubframe insertion portion 112 a of the subframe rod 112 arerespectively inserted into the insertion holes 113 a and 113 b of therubber member 113, and that the silencer 44 is supported on the rearsubframe 50 via the rubber member 113.

FIG. 19 is an explanatory diagram illustrating how the silencer moves inrear collision. As illustrated in the section (a) of FIG. 19, in a casewhere a collision load is applied from rearwardly of the vehicle body inrear collision of the vehicle body 1, the collision load is input to therear side frame 2 by deformation of the vehicle body rear part, and thecollision load is also input to the rear subframe 50.

When the collision load is input to the rear subframe 50, as illustratedin the section (b) of FIG. 19, the subframe bumper reinforcement 18 ofthe rear subframe 50 is moved forwardly of the vehicle body, and therear load absorbing portion 54 b of the rear subframe 50 provokes abuckling distortion in the vehicle body front-rear direction, so thatthe collision load is absorbed.

When the subframe bumper reinforcement 18 of the rear subframe 50 ismoved forwardly of the vehicle body, the subframe insertion allowingportion 112 b provided on the subframe rod 112 of the rear supporthanger 110 is moved forwardly of the vehicle body, and is inserted intothe insertion hole 113 b of the rubber member 113. Thus, the rear loadabsorbing portion 54 b of the rear subframe 50 absorbs the collisionload, without moving the silencer rod 111 of the rear support hanger110.

As illustrated in the section (c) of FIG. 19, when the subframe bumperreinforcement 18 of the rear subframe 50 is further moved forwardly ofthe vehicle body, the front load absorbing portion 54 a of the rearsubframe 50 provokes a buckling distortion in the vehicle bodyfront-rear direction, to absorb the collision load. In addition, thesilencer 44 and the catalytic device 45 are moved forwardly of thevehicle body. However, the silencer 44 and the catalytic device 45 aremoved downwardly of the vehicle body along the guide portion 91, asbeing moved forwardly of the vehicle body.

When the subframe bumper reinforcement 18 is further moved forwardly ofthe vehicle body, the subframe rod 112 is restrained from being insertedinto the rubber member 113 by the elastic body insertion restrainingportion 112 c provided on the subframe rod 112 of the rear supporthanger 110, and the rubber member 113 is restrained from movingforwardly of the vehicle body by the elastic body movement restrainingportion 111 b provided on the silencer rod 111 of the rear supporthanger 110. Thus, the silencer 44 and the catalytic device 45 are moveddownwardly of the vehicle body along the guide portion 91, as movingforwardly of the vehicle body, and the silencer rod 111 of the rearsupport hanger 110 is detached from the rubber member 113.

In the vehicle body 1 configured as described above, in a case where acollision load is applied from rearwardly of the vehicle body in rearcollision, when the collision load is input to the rear side frame 2,the collision load is absorbed by the load absorbing portion 6 providedon the rear side frame 2, and the load input to the rear side frame 2 istransmitted and dispersed to a vehicle body front part of the rear sideframe 2.

Furthermore, after the load absorbing portion 6 provided on the rearside frame 2 starts buckling distortion, the collision load is alsoinput to the rear subframe 50, the load absorbing portion 54 provided onthe rear subframe 50 provokes buckling distortion to absorb thecollision load. In the rear subframe 50, after the rear load absorbingportion 54 b provokes buckling distortion, the front load absorbingportion 54 a provokes buckling distortion to absorb the collision load.

The load input to the rear subframe 50 is transmitted from the upperframe member 51 of the rear subframe 50 to the vehicle body front side,transmitted to the rear side frame 2 connected to a vehicle body frontpart of the rear subframe 50, and transmitted to the vehicle body frontside; and is transmitted from the upper frame member 51 of the rearsubframe 50 to the lower frame member 71 via the branch frame member 61,and transmitted from the lower frame member 71 to the battery frame 30.In this case, the load input to the branch frame member 61 is mainlytransmitted to the lower frame member 71 from the rear surface portion62 and the lateral surface portions 65 in the vicinity of both sidesthereof via the bottom surface portion 64 and the lateral surfaceportions 65 in the vicinity of both sides thereof.

The load input to the rear subframe 50 is also transmitted to the rearsurface portion 62 and the lateral surface portions 65 in the vicinityof both sides thereof of the branch frame member 61 via the upper crossportion 53 and the guide portion 91, transmitted to the lower framemember 71, and transmitted from the lower frame member 71 to the batteryframe 30.

Furthermore, when a collision load is applied from rearwardly of thevehicle body to the guide portion 91 in rear collision, the collisionload input to the guide portion 91 is transmitted to the rear surfaceportion 62 and the lateral surface portions 65 in the vicinity of bothsides thereof of the branch frame member 61, transmitted to the lowerframe member 71, and transmitted from the lower frame member 71 to thebattery frame 30; and is transmitted from the upper cross portion 53 tothe upper frame member 51 of the rear subframe 50, and transmitted toeach part of the rear subframe 50.

In the vehicle body 1 according to the present embodiment, asillustrated in FIG. 2, the rear subframe 50 disposed below the rear sideframe 2 includes the front load absorbing portion 54 a and the rear loadabsorbing portion 54 b which extend rearwardly of the vehicle body withrespect to an important safety related component, that is, the rangeextender device 40 (hereinafter, referred to as an important safetyrelated component 40), disposed on the vehicle body rear part, and aredisposed on the vehicle body rear side with respect to the importantsafety related component 40. Strength of the rear load absorbing portion54 b against compression in the axis direction is set low, as comparedwith that of the front load absorbing portion 54 a.

As illustrated in FIG. 8, the rear subframe 50 includes the rear frameconnecting portion 56 b which is disposed between the front loadabsorbing portion 54 a and the rear load absorbing portion 54 b, isconnected to the front load absorbing portion 54 a and the rear loadabsorbing portion 54 b, and is connected to the rear side frame 2. Theframe connecting portion 56 b is constituted by the frame connectingmember 80.

In this way, in the vehicle body rear part structure for a vehicleaccording to the present embodiment, the rear subframe 50 disposed belowthe rear side frame 2 includes the front load absorbing portion 54 a andthe rear load absorbing portion 54 b extending rearwardly of the vehiclebody with respect to the important safety related component 40 disposedon the vehicle body rear part, and disposed on the vehicle body rearside with respect to the important safety related component 40. Strengthof the rear load absorbing portion 54 b against compression in the axisdirection is set low, as compared with that of the front load absorbingportion 54 a.

With this configuration, in the rear subframe 50, the front loadabsorbing portion 54 a provokes buckling distortion, after the rear loadabsorbing portion 54 b away from the important safety related component40 provokes buckling distortion in rear collision. Therefore, thecollision load is absorbed by the rear load absorbing portion 54 b andthe front load absorbing portion 54 a of the rear subframe 50 in thisorder in rear collision, and it is possible to protect the importantsafety related component 40 disposed on the vehicle body rear part bythe rear subframe 50. Furthermore, the collision load is absorbed by therear load absorbing portion 54 b and the front load absorbing portion 54a of the rear subframe 50 in this order in rear collision, and it ispossible to improve safety of a passenger within a passenger compartmentby the rear subframe 50.

In addition, the rear subframe 50 includes the rear frame connectingportion 56 b which is disposed between the front load absorbing portion54 a and the rear load absorbing portion 54 b, is connected to the frontload absorbing portion 54 a and the rear load absorbing portion 54 b,and is connected to the rear side frame 2. With this configuration, thefront load absorbing portion 54 a and the rear load absorbing portion 54b are connected to the rear frame connecting portion 56 b connected tothe rear side frame 2. Thus, bending rigidity can be increased, ascompared with a case where the front load absorbing portion 54 a and therear load absorbing portion 54 b are integrally formed. Hence, it ispossible to effectively cause the rear load absorbing portion 54 b andthe front load absorbing portion 54 a to provoke buckling distortion inrear collision.

Furthermore, the rear frame connecting portion 56 b includes the loadtransmitting portion 84 extending in the vehicle body front-reardirection. The load transmitting portion 84 is formed to have a sameclosed cross section shape as a closed cross-sectional portion of thefront load absorbing portion 54 a and a closed cross-sectional portionof the rear load absorbing portion 54 b. With this configuration, it ispossible to effectively transmit the collision load from the rear loadabsorbing portion 54 b to the front load absorbing portion 54 a in rearcollision. In addition, it is possible to increase bending rigidity, ascompared with a case where the load transmitting portion 84 is formed tohave a cross section shape different from a closed cross-sectionalportion of the front load absorbing portion 54 a and a closedcross-sectional portion of the rear load absorbing portion 54 b, and toeffectively cause the rear load absorbing portion 54 b and the frontload absorbing portion 54 a to provoke buckling distortion in rearcollision.

Furthermore, a closed cross-sectional portion of the front loadabsorbing portion 54 a, a closed cross-sectional portion of the rearload absorbing portion 54 b, and the load transmitting portion 84 of therear frame connecting portion 56 b are formed into a polygonal shape incross section having sides of a number larger than the number of sidesof a rectangular shape in cross section. With this configuration, it ispossible to increase strength against compression in the axis directionby increasing the number of ridge lines, as compared with a case wherethe above-described portions are formed into a rectangular shape incross section, and it is possible to more effectively acquire theabove-described advantageous effects.

Moreover, if it is assumed that the load transmitting portion 84 isjoined to the peripheral wall portion 83 by a flange portion provided oneach of an end of a vehicle body front side of the load transmittingportion 84 and an end of a vehicle body rear side of the loadtransmitting portion 84, stress may be concentratedly applied to aportion other than the flange portions of the end of the vehicle bodyfront side and the end of the vehicle body rear side of the loadtransmitting portion 84 in rear collision, to cause deformation, whichmay makes it impossible to effectively absorb the collision load.However, according to the above embodiment, since a vehicle body frontside of the load transmitting portion 84 is abutted on and joined to avehicle body front side of the peripheral wall portion 83, and a vehiclebody rear side of the load transmitting portion 84 is abutted on andjointed to a vehicle body rear side of the peripheral wall portion 83,it is possible to suppress concentration of stress, and to effectivelyabsorb the collision load by the front load absorbing portion 54 a andthe rear load absorbing portion 54 b in rear collision.

In addition, the accessories 44 and 45 except for the important safetyrelated component 40 are disposed at a position where the accessories 44and 45 overlap the front load absorbing portion 54 a in the vehicle bodyfront-rear direction. With this configuration, it is possible to protectthe important safety related component 40 in rear collision, and toprevent damage of the accessories 44 and 45 disposed at a position wherethe accessories 44 and 45 overlap the front load absorbing portion 54 ain the vehicle body front-rear direction, when only the rear loadabsorbing portion 54 b provokes buckling distortion.

Next, a vehicle body rear part structure for a vehicle according to asecond embodiment of the present invention is described.

FIG. 20 is a bottom view of a vehicle body to which the vehicle bodyrear part structure for a vehicle according to the second embodiment ofthe present invention is applied. FIG. 21 is a side view of the vehiclebody to which the above vehicle body rear part structure is applied.FIG. 22 is a perspective view illustrating essential parts of the abovevehicle body rear part structure. A basic vehicle body rear partstructure according to the second embodiment is the same as the vehiclebody rear part structure according to the first embodiment. Therefore,in the following description, constituent elements common to those inthe vehicle body rear part structure according to the first embodimentare indicated with same reference numerals, and description thereof isomitted or simplified; and mainly differences with respect to the firstembodiment are described.

In the above-described first embodiment, the upper cross portion 53 ofthe rear subframe 50 is constituted by the front frame connectingportions 56 a (frame connecting members 80) respectively joined to frontsurfaces of the left and right front load absorbing portion 54 a; andthe sub cross member 90 of a closed cross section, which is joined andconnected to these front frame connecting portions 56 a. On the otherhand, in the second embodiment, an upper cross portion 53 is constitutedby a cross reinforcement 120, which extends in a vehicle width directionand is joined to each of front surfaces of left and right front loadabsorbing portions 54 a; and a frame member 122 which is joined to afront surface of the cross reinforcement 120 in a vehicle bodyfront-rear direction and extends in the vehicle width direction.Therefore, in a rear subframe 50 in the second embodiment, a sub crossmember 90 and a front frame connecting portion 56 a are not provided.

The frame member 122 has a U-shape in cross section, and is joined to afront surface of the cross reinforcement 120. With this configuration,the upper cross portion 53 is formed into a closed cross section of asubstantially rectangular shape in cross section extending in thevehicle width direction (see FIG. 23).

A connecting bracket 124 is joined to each of both ends of the uppercross portion 53 in the vehicle width direction. The connecting bracket124 is constituted of a first bracket 125 and a second bracket 126. Thefirst bracket 125 has an inverted L-shape in cross section when viewedfrom forwardly of the vehicle body, and includes a vertical surfaceportion 125 a extending vertically, and a lateral surface portion 125 bextending outwardly in the vehicle width direction from an upper end ofthe vertical surface portion 125 a. The first bracket 125 is joined tothe frame member 122 and the cross reinforcement 120 in a state that thevertical surface portion 124 a and the lateral surface portion 124 bcome into contact with a cutout portion formed in an end of the framemember 122. On the other hand, the second bracket 126 has an invertedU-shape in cross section when viewed from forwardly of the vehicle body,and includes an upper surface portion 126 a extending forwardly of thevehicle body along the lower surface portion 2 a of the rear side frame2, and a pair of left and right side surface portions 126 b suspendingfrom both ends of the upper surface portion 126 in the vehicle widthdirection. The second bracket 126 is disposed above the first bracket125 in such a way that an end portion 122 a of the frame member 122 issandwiched by the side surface portions 126 b and the lateral surfaceportion 125 b of the first bracket 125. The second bracket 126 is joinedto each of the lateral surface portion 125 b of the first bracket 125,the frame member 122, and the cross reinforcement 120.

The upper cross portion 53 is connected to the rear side frame 2 via theconnecting bracket 124 at positions of both ends of the upper crossportion 53 in the vehicle width direction. Specifically, the uppersurface portion 126 a of the second bracket 126 and the lower surfaceportion 2 a of the rear side frame 2 are engaged to each other by a boltB6 and an unillustrated nut, and the lateral surface portion 125 b ofthe first bracket 125 and the lower surface portion 2 a of the rear sideframe 2 are engaged to each other by a bolt B7 and an unillustrated nut.A tubular member 128 is interposed between the lateral surface portion125 b of the first bracket 125 and the upper surface portion 126 a ofthe second bracket 126, while passing through the frame member 122. Thebolt B7 engaging the first bracket 125 and the rear side frame 2 isscrewed in a nut fixed to the rear side frame 2 through the tubularmember 128.

In the second embodiment, as illustrated in FIG. 21, the front loadabsorbing portion 54 a is formed into such a shape that a vertical sizethereof gradually increases, as the front load absorbing portion 54 aextends forwardly from a rear side in the vehicle body front-reardirection, and includes a flange portion 129 on a front end thereof. Inthe second embodiment, the front load absorbing portion 54 a isconnected to the upper cross portion 53 by engaging the flange portion129 to the cross reinforcement 120 by an unillustrated bolt and anunillustrated nut.

In the above-described first embodiment, the rear subframe 50 includes:the upper frame portion 52 connected to each of front portions of theleft and right front frame connecting portions 56 a and extending in thevehicle body front-rear direction; the branch frame member 61 connectedto the upper frame portion 52; and the lower frame member 71 extendingsubstantially horizontally from the branch frame member 61 and forwardlyof the vehicle body. However, in the second embodiment, the rearsubframe 50 does not include an upper frame portion 52 and a branchframe member 61. The lower frame member 71 directly extends from theupper cross portion 53 forwardly of the vehicle body and obliquelydownwardly.

The lower frame member 71 includes: a rear portion 711 extending fromthe upper cross portion 53 forwardly and downwardly of the vehicle body;an intermediate portion 712 extending from a front end of the rearportion 711 forwardly and downwardly of the vehicle body with a largerangle with respect to a horizontal plane, as compared with the lowerframe member 711; and a front portion 713 extending from a front end ofthe intermediate portion 712 substantially horizontally and forwardly ofthe vehicle body.

Furthermore, in the first embodiment, the lower frame member 71 has aflat shape vertically, and is formed in such a way that a lateral width(a size in the vehicle width direction) increases, as extendingforwardly of the vehicle body in a certain area on the vehicle bodyfront side. However, in the second embodiment, as illustrated in FIGS.20 and 21, the lower frame member 71 has a closed cross section of arectangular shape in cross section in which a lateral width thereof (asize in the vehicle width direction) is substantially the same over theentire area in the front-rear direction in a state that the lateralwidth is slightly large, as compared with a vertical size. In addition,the front portion 713 of the lower frame member 71 is formed in such away that a vertical size thereof increases, as extending forwardly fromthe vehicle body rear side. Specifically, a lower surface of the lowerframe member 71 is formed into a substantially horizontal surface, andan upper surface thereof is formed obliquely upwardly, as extendingforwardly from the vehicle body rear side with respect to the lowersurface as a reference.

As illustrated in FIG. 22, connecting flanges 130 and 132 (a frontflange 130 and a rear flange 132) are provided on a front end and a rearend of the lower frame member 71 in the vehicle body front-reardirection. As illustrated in FIG. 24, the front flange 130 is formedinto an L-shape in cross section in such a way as to come into contactwith a rear surface and a lower surface of a battery frame 30, morespecifically, a rear surface and a lower surface of a rear frame 31. Thefront flange 130 is fixed to the battery frame 30 by a bolt B8 and a nutN8 fixed inside the rear frame 31. With this configuration, a front endof the lower frame member 71 is connected to the battery frame 30.

On the other hand, the rear flange 132 is formed to have a shape inconformity with front surfaces of the frame member 122 and the crossreinforcement 120 of the upper cross portion 53. As illustrated in FIG.23, the rear flange 132 is fixed to the upper cross portion 53 by a boltB9 and a nut N9 that is fixed inside the upper cross portion 53 (framemember 122), and a bolt B10 and a nut N10 that is fixed to a rearsurface of the cross reinforcement 120. With this configuration, a rearend of the lower frame member 71 is connected to the upper cross portion53.

In the vehicle body rear part structure according to the secondembodiment, although there is a point different from the vehicle bodyrear part structure according to the first embodiment, operations andadvantageous effects substantially equivalent to those in the firstembodiment are provided.

Specifically, when a collision load is applied from rearwardly of thevehicle body in rear collision, after the load absorbing portion 6provided on the rear side frame 2 starts buckling distortion, thecollision load is also input to the rear subframe 50, and the loadabsorbing portion 54 provided on the rear subframe 50 provokes bucklingdistortion to absorb the collision load. In the rear subframe 50, afterthe rear load absorbing portion 54 b provokes buckling distortion, thefront load absorbing portion 54 a provokes buckling distortion, so thatthe collision load is absorbed.

The load input to the rear subframe 50 is transmitted from the uppercross portion 53 of the rear subframe 50 to the rear side frame 2 viathe connecting bracket 124 to be transmitted to the vehicle body frontside, and is transmitted from the upper cross portion 53 of the rearsubframe 50 to the battery frame 30 via the lower frame member 71.Therefore, it is possible to suppress deformation of the rear subframe50 by dispersing the load input to the rear subframe 50 upwardly of thevehicle body and downwardly of the vehicle body on the vehicle bodyfront side, to protect the accessories 40, 44, and 45 disposed on thevehicle body rear part, when the accessories 40, 44, and 45 are disposedon the vehicle body front side with respect to a rear end of the rearsubframe 50 on the vehicle body rear part, and to improve safety of apassenger within a passenger compartment.

The present embodiments describe a vehicle such as an electric vehiclein which the range extender device 40 is disposed on a vehicle body rearpart. The present invention is also applicable to a vehicle such asanother type of electric vehicle in which an accessory, which is animportant safety related component, such as a fuel tank, an electricalstorage device, and the like, is disposed on a vehicle body rear part.

The present invention is not limited to the exemplified embodiments, andvarious improvements and design modifications are available as far asthe improvements and design modifications do not depart from the gist ofthe present invention.

The following is an overview of the present invention described above.

The present invention is directed to a vehicle body rear part structurefor a vehicle including a rear side frame extending in a vehicle bodyfront-rear direction on a vehicle body rear part, and a rear subframedisposed below the rear side frame and extending in the vehicle bodyfront-rear direction. The rear subframe includes a front load absorbingportion and a rear load absorbing portion which extend rearwardly of avehicle body from an important safety related component disposed on thevehicle body rear part, are disposed on a vehicle body rear side withrespect to the important safety related component, and are configured toabsorb a collision load when the collision load from rearwardly of thevehicle body is applied. The rear load absorbing portion is disposed onthe vehicle body rear side of the front load absorbing portion. Strengthof the rear load absorbing portion against compression in an axisdirection is set low, as compared with strength of the front loadabsorbing portion.

According to this configuration, the rear subframe disposed below therear side frame includes the front load absorbing portion and the rearload absorbing portion extending rearwardly of the vehicle body from theimportant safety related component disposed on the vehicle body rearpart, and disposed on the vehicle body rear side with respect to theimportant safety related component. Strength of the rear load absorbingportion against compression in the axis direction is set low, ascompared with strength of the front load absorbing portion.

With this configuration, in the rear subframe, the front load absorbingportion can be provoked buckling distortion, after the rear loadabsorbing portion away from the important safety related componentprovokes buckling distortion in rear collision. Thus, the collision loadis absorbed by the rear load absorbing portion and the front loadabsorbing portion of the rear subframe in this order in rear collision.Hence, it is possible to protect the important safety related componentdisposed on the vehicle body rear part by the rear subframe. Inaddition, the collision load is absorbed by the rear load absorbingportion and the front load absorbing portion of the rear subframe inthis order in rear collision. Hence, it is possible to improve safety ofa passenger within a passenger compartment by the rear subframe.

In the above vehicle body rear part structure for a vehicle, the rearsubframe includes a frame connecting portion which is disposed betweenthe front load absorbing portion and the rear load absorbing portion, isconnected to the front load absorbing portion and the rear loadabsorbing portion, and is connected to the rear side frame.

According to this configuration, the rear subframe is provided with theframe connecting portion which is disposed between the front loadabsorbing portion and the rear load absorbing portion, is connected tothe front load absorbing portion and the rear load absorbing portion,and is connected to the rear side frame. With this configuration, thefront load absorbing portion and the rear load absorbing portion areconnected to the frame connecting portion connected to the rear sideframe. Thus, bending rigidity is increased, as compared with a casewhere the front load absorbing portion and the rear load absorbingportion are integrally formed. Hence, it is possible to effectivelycause the rear load absorbing portion and the front load absorbingportion to provoke buckling distortion in rear collision.

In the above body rear part structure for a vehicle, each of the frontload absorbing portion and the rear load absorbing portion includes aclosed cross-sectional portion which is formed into a closed crosssection on an orthogonal cross section orthogonal to the vehicle bodyfront-rear direction. The frame connecting portion includes a loadtransmitting portion which extends in the vehicle body front-reardirection, and is configured to transmit a collision load from the frontload absorbing portion to the rear load absorbing portion, when thecollision load from rearwardly of the vehicle body is applied. The loadtransmitting portion is formed to have a same cross section as theclosed cross-sectional portion of the front load absorbing portion andthe closed cross-sectional portion of the rear load absorbing portion onthe orthogonal cross section orthogonal to the vehicle body front-reardirection.

According to this configuration, the frame connecting portion includesthe load transmitting portion extending in the vehicle body front-reardirection. The load transmitting portion is formed to have a same crosssection as the closed cross-sectional portion of the front loadabsorbing portion and the closed cross-sectional portion of the rearload absorbing portion. Therefore, it is possible to effectivelytransmit the collision load from the rear load absorbing portion to thefront load absorbing portion in rear collision. Furthermore, it ispossible to increase bending rigidity, as compared with a case where theload transmitting portion is formed to have a cross section differentfrom a closed cross-sectional portion of the front load absorbingportion and a closed cross-sectional portion of the rear load absorbingportion, and to effectively cause the rear load absorbing portion andthe front load absorbing portion to provoke buckling distortion in rearcollision.

In the above vehicle body rear part structure for a vehicle, each of theclosed cross-sectional portion of the front load absorbing portion, theclosed cross-sectional portion of the rear load absorbing portion, andthe load transmitting portion of the frame connecting portion is formedinto a polygonal shape in cross section having sides of a number largerthan the number of sides of a rectangular shape in cross section. Theframe connecting portion includes a peripheral wall portion formed intoa closed cross section on an orthogonal cross section orthogonal to avehicle width direction. The frame connecting portion is formed withinthe peripheral portion in such a way that a vehicle body front portionof the load transmitting portion is abutted on and jointed to a vehiclebody front portion of the peripheral wall portion, and that a vehiclebody rear portion of the load transmitting portion is abutted on andjoined to a vehicle body rear portion of the peripheral wall portion.

According to this configuration, each of the closed cross-sectionalportion of the front load absorbing portion, the closed cross-sectionalportion of the rear load absorbing portion, and the load transmittingportion of the frame connecting portion is formed into a polygonal shapein cross section having sides of a number larger than the number ofsides of a rectangular shape in cross section. Thus, it is possible toincrease strength against compression in the axis direction byincreasing the number of ridge lines, as compared with a case where theabove-described portions are formed into a rectangular shape in crosssection, and it is possible to more effectively acquire theabove-described advantageous effects.

Moreover, if it is assumed that the load transmitting portion is joinedto the peripheral wall portion by a flange portion provided on each ofan end of a vehicle body front side of the load transmitting portion andan end of a vehicle body rear side of the load transmitting portion,stress may be concentratedly applied to a portion other than the flangeportions of the end of the vehicle body front side and the end of thevehicle body rear side of the load transmitting portion in rearcollision, to cause deformation, which may makes it impossible toeffectively absorb the collision load. However, according to the aboveconfiguration, since a vehicle body front side of the load transmittingportion is abutted on and joined to a vehicle body front side of theperipheral wall portion, and a vehicle body rear side of the loadtransmitting portion is abutted on and jointed to a vehicle body rearside of the peripheral wall portion, it is possible to suppressconcentration of stress, and to effectively absorb the collision load bythe front load absorbing portion and the rear load absorbing portion inrear collision.

In the above vehicle body rear part structure for a vehicle, anaccessory which excludes the important safety related component, and isdisposed at a position where the accessory overlaps the front loadabsorbing portion in the vehicle body front-rear direction, is furtherincluded.

According to this configuration, an accessory which excludes theimportant safety related component, and is disposed at a position wherethe accessory overlaps the front load absorbing portion in the vehiclebody front-rear direction, is further included. Thus, it is possible toprotect the important safety related component in rear collision, and toprevent damage of the accessory disposed at a position where theaccessory overlaps the front load absorbing portion in the vehicle bodyfront-rear direction, when only the rear load absorbing portion provokesbuckling distortion.

In the above vehicle body rear part structure for a vehicle, the rearsubframe includes a cross portion which extends in a vehicle widthdirection below the rear side frame and at a position of a vehicle bodyrear side with respect to the important safety related component, bothends of which are connected to the rear side frame, and is formed into aclosed cross section. A front end of the front load absorbing portion isconnected to the cross portion.

According to this configuration, it is possible to successfully causethe front load absorbing portion and the rear load absorbing portion toprovoke buckling distortion, while receiving the load from the crossportion connected to the rear subframe. Therefore, it is possible toeffectively protect the important safety related component disposed onthe vehicle body rear part by the rear subframe.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, in a vehicleprovided with a rear subframe disposed below a rear side frame, it ispossible to protect an important safety related component, and toimprove safety of a passenger within a passenger compartment byabsorbing a collision load in rear collision. Therefore, there is apossibility that the present invention is advantageously used in theindustrial field of manufacturing a vehicle of this type.

1. A vehicle body rear part structure for a vehicle, comprising: a rearside frame which extends in a vehicle body front-rear direction on avehicle body rear part; a rear subframe which is disposed below the rearside frame, and extends in the vehicle body front-rear direction; atorsion beam suspension device which is disposed on a vehicle body rearpart, and includes a torsion beam extending in a vehicle widthdirection; and an important safety related component which is disposedon a vehicle body rear side of the torsion beam, and is mounted on therear subframe, wherein the rear subframe includes a front load absorbingportion and a rear load absorbing portion which extend rearwardly of avehicle body from the important safety related component disposed on thevehicle body rear part, are disposed on a vehicle body rear side withrespect to the important safety related component, and are configured toabsorb a collision load when the collision load from rearwardly of thevehicle body is applied, the important safety related component includesat least one of a power generator and an electrical storage device, therear load absorbing portion is disposed on the vehicle body rear side ofthe front load absorbing portion, and strength of the rear loadabsorbing portion against compression in an axis direction is set low,as compared with strength of the front load absorbing portion.
 2. Thevehicle body rear part structure for a vehicle according to claim 1,wherein the rear subframe includes a frame connecting portion which isdisposed between the front load absorbing portion and the rear loadabsorbing portion, is connected to the front load absorbing portion andthe rear load absorbing portion, and is connected to the rear sideframe.
 3. The vehicle body rear part structure for a vehicle accordingto claim 2, wherein each of the front load absorbing portion and therear load absorbing portion includes a closed cross-sectional portionwhich is formed into a closed cross section on an orthogonal crosssection orthogonal to the vehicle body front-rear direction, the frameconnecting portion includes a load transmitting portion which extends inthe vehicle body front-rear direction, and is configured to transmit acollision load from the front load absorbing portion to the rear loadabsorbing portion, when the collision load from rearwardly of thevehicle body is applied, and the load transmitting portion is formed tohave a same cross section as the closed cross-sectional portion of thefront load absorbing portion and the closed cross-sectional portion ofthe rear load absorbing portion on the orthogonal cross sectionorthogonal to the vehicle body front-rear direction.
 4. The vehicle bodyrear part structure for a vehicle according to claim 3, wherein each ofthe closed cross-sectional portion of the front load absorbing portion,the closed cross-sectional portion of the rear load absorbing portion,and the load transmitting portion of the frame connecting portion isformed into a polygonal shape in cross section having sides of a numberlarger than the number of sides of a rectangular shape in cross section,the frame connecting portion includes a peripheral wall portion formedinto a closed cross section on an orthogonal cross section orthogonal toa vehicle width direction, and the frame connecting portion is formedwithin the peripheral wall portion in such a way that a vehicle bodyfront portion of the load transmitting portion is abutted on and jointedto a vehicle body front portion of the peripheral wall portion, and thata vehicle body rear portion of the load transmitting portion is abuttedon and joined to a vehicle body rear portion of the peripheral wallportion.
 5. The vehicle body rear part structure for a vehicle accordingto claim 1, further comprising an accessory which excludes the importantsafety related component, and is disposed at a position where theaccessory overlaps the front load absorbing portion in the vehicle bodyfront-rear direction.
 6. The vehicle body rear part structure for avehicle according to claim 1, wherein the rear subframe includes a crossportion which extends in a vehicle width direction below the rear sideframe and at a position of a vehicle body rear side with respect to theimportant safety related component, both ends of which are connected tothe rear side frame, and is formed into a closed cross section, and afront end of the front load absorbing portion is connected to the crossportion.
 7. The vehicle body rear part structure for a vehicle accordingto claim 2, further comprising an accessory which excludes the importantsafety related component, and is disposed at a position where theaccessory overlaps the front load absorbing portion in the vehicle bodyfront-rear direction.
 8. The vehicle body rear part structure for avehicle according to claim 3, further comprising an accessory whichexcludes the important safety related component, and is disposed at aposition where the accessory overlaps the front load absorbing portionin the vehicle body front-rear direction.
 9. The vehicle body rear partstructure for a vehicle according to claim 4, further comprising anaccessory which excludes the important safety related component, and isdisposed at a position where the accessory overlaps the front loadabsorbing portion in the vehicle body front-rear direction.
 10. Thevehicle body rear part structure for a vehicle according to claim 2,wherein the rear subframe includes a cross portion which extends in avehicle width direction below the rear side frame and at a position of avehicle body rear side with respect to the important safety relatedcomponent, both ends of which are connected to the rear side frame, andis formed into a closed cross section, and a front end of the front loadabsorbing portion is connected to the cross portion.
 11. The vehiclebody rear part structure for a vehicle according to claim 3, wherein therear subframe includes a cross portion which extends in a vehicle widthdirection below the rear side frame and at a position of a vehicle bodyrear side with respect to the important safety related component, bothends of which are connected to the rear side frame, and is formed into aclosed cross section, and a front end of the front load absorbingportion is connected to the cross portion.
 12. The vehicle body rearpart structure for a vehicle according to claim 4, wherein the rearsubframe includes a cross portion which extends in a vehicle widthdirection below the rear side frame and at a position of a vehicle bodyrear side with respect to the important safety related component, bothends of which are connected to the rear side frame, and is formed into aclosed cross section, and a front end of the front load absorbingportion is connected to the cross portion.
 13. The vehicle body rearpart structure for a vehicle according to claim 5, wherein the rearsubframe includes a cross portion which extends in a vehicle widthdirection below the rear side frame and at a position of a vehicle bodyrear side with respect to the important safety related component, bothends of which are connected to the rear side frame, and is formed into aclosed cross section, and a front end of the front load absorbingportion is connected to the cross portion.